Want to cut your risk of obesity in half -- and drop your risk of cardiovascular disease, keep your blood pressure and insulin levels healthy and make your memory more vibrant in the process?

Forget where you put your car keys. Or lose them altogether.

In a new study, men saw these big benefits just by walking or bicycling to work ... even if they lived close by. The median distance of their commutes was just five miles, and the median time was 20 minutes.

What about women? Well, the benefits of what the researchers call "active commuting" (that's walking or biking, not cleaning up spilled coffee, applying lipstick or reaching to the floor of your car for the Froot Loop you just dropped) were less clear for women.

Female active commuters did have higher fitness levels than people who didn't get to work under their own power, but the effect on heart disease was less clear. It might be because the study didn't have enough women to show any effect -- or it could be that women walk or bike at a lower intensity level.

That doesn't mean you shouldn't do it. In fact, it might mean you need to do it more, and more actively, than the guys around you do.

And guys, it's likely that the reduction in fat around the male participants' bellies is what lowered heart disease risk. So sorry: Walking by the Dunkin' Donuts doesn't mean you get to stop in as a reward. But it does mean you might live longer and better. And that's a reward that works for us.

The YOU Docs -- Mike Roizen and Mehmet Oz -- are authors of "YOU: Being Beautiful -- The Owner's Manual to Inner and Outer Beauty." To submit questions and find ways to grow younger and healthier, go to www.RealAge.com, the docs' online home.

National Video